The attacker, named as Khamzat Azimov, 20, struck in one of the most popular areas of the city, near the celebrated opera house and theatres, before before being shot dead by police in Paris.

Police said he was previously interviewed because of his contacts , not his behaviour, and they insisted he had shown no signs of extremism in his everyday life or on social media.

Azimov, was listed as a person susceptible to Islamic radicalisation, but” more for the company he keeps than for his own behaviour, his actions or his opinions”, according to a report in Le Figaro.

French police took the man’s parents into custody on Sunday for questioning about his links to jihadists in Syria and searched the family home in the 18 th arrondissement in the north of Paris. One of Azimov’s friends from Strasbourg, where he grew up, was also reportedly detained for questioning.

Azimov struck at random in the busy region of restaurants and theatres near Paris’s Opera Garnier in the city’s second arrondissement, at about 8.50 pm local time.

Witnesses told Azimov, who was born in Chechnya, but procured French nationality in 2010 when his mother was naturalised, arrived at the scene of the attack by metro. He was dressed in black, and carrying a knife.

Police were quick to arrive at the scene as he strolled along rue Monsigny, a one-way street, apparently looking for victims. Panicked diners fled terraces or took refuge under tables inside restaurants.

Officers, praised for their sangfroid, reportedly tried to halt him with a stun-gun, but when he continued to threaten them shot him dead.

Born in the Caucuses, Azimov’s family came to France in the early 2000 s and moved to Nice before settling on a housing estate at Elsau, in the eastern French city of Strasbourg, home to a large number of Chechen migrants. The family’s request for refugee status was initially refused; on appeal it was finally approved by the National Court for the Right to Asylum in 2004. Azimov’s father was refused French nationality after separating from the boy’s mother. Le Monde said the couple had since reunited and moved to a new home in the north of Paris.

Although he had never been in trouble with the police or the authorities and had no criminal record, he had come to the attention of French security services because of his contacts with a group of young people wanting to travel to Syria.

Azimov, who was not carrying identity papers, had been interviewed by counter-terrorism policemen a year ago after it was discovered he was friends with a human whose wife had travelled to Syria. He had been on the Fiche-S list of people considered a potential security danger since 2016 but was considered a suiveur ( follower ), or secondary figure, according to anti-terrorist policemen. He had no criminal record.

Up to 20,000- from radical Islamists to hooligans and members of the extreme right or extreme left- people are believed to be on the Fiche S listing and classified according to their potential danger.

In a series of tweets, the French chairperson, Emmanuel Macron, said his thoughts were with the victims of the attack and praised the courage of police who” neutralised the terrorist “.

” France is paying in blood is again, but it will not give one inch to the enemies of liberty ,” he wrote.

The interior minister, Gerard Collomb, hailed the sangfroid and quick reaction of police who shot the attacker.” My first believes are with the victims of this odious act ,” he tweeted.

Another woman who was out with her young son and ensure the knifeman said he seemed determined to assault police officers who had tried to surround and immobilise him.

” Police surrounded him and I truly thought that would stop him, but not at all. He literally jumped at the police. He was so determined ,” she told BFM TV.

She added:” He was small, slim, longish hair, like all the fashionable young, a three-day beard. He did not stand out. He was garmented ordinarily. Never in my life would I have thought he was going to attack .”